The proposed project is a multidisciplinary study of trophoblastic disease. Chemotherapy trials in high risk and in metastatic choriocarcinoma using untried agents and adjuvant radiation therapy will be conducted. In low risk patients, alternating methotrexate and actinomycin D will be employed. HLA-A,B,C,D and B cell (Ia) typing will done. A study will be made of our observation that patients' sera enhances rather than inhibits in mixed lymphocyte culture response and to study factors relating to this stimulating ability. the effect of peripheral blood lymphocytes and their products on excretion of hCG by tissue culture cell lines will be investigated. The carboxyl terminal hCB B tryptic peptide method will be used to measure hCG-like substances in the sera and urine of patients with trophoblastic disease and to compare these with levels measured by hCG/LH and Specific hCG methods.